These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.00 s (backtrack: 0/20).

[ebuild  N     ] sci-libs/blis-2.1:0/4-2.0::gentoo  USE="openmp -doc -eselect-ldso -index64 -pthread -serial -static-libs" CPU_FLAGS_X86="avx avx2 avx512vl fma3 ssse3 -fma4" 15390 KiB

Total: 1 package (1 new), Size of downloads: 15390 KiB